ABSTRACT Inflammatory Bowel Disease (IBD) comprises a collection of chronic autoimmune disorders that afflicts an estimated 1.5-3 million Americans, and incidences are rising. In IBD patients, dysfunction of the immune system affects the gastrointestinal (GI) tract causing diarrhea, abdominal pain and rectal bleeding, while the list of potential extraintestinal complications includes osteoporosis, kidney stones, joint pain and various soft-tissue ailments. The complications can be serious, and more than 1 in 10 IDB patients will require surgery within five years of diagnosis. Moreover, depression and elevated stress levels can contribute to disease flares. There are no cures for IBD, but several categories of pharmacological treatment are available, most of which cause terrible side effects, are not very effective, or both. In this SBIR project, Senti Biosciences will deploy its proprietary cell engineering technologies to create a safer and more efficacious IBD therapy. These technologies are engineered to accelerate the speed and precision at of genetic control circuits implemented into living cells. Gene circuit technologies can turn mammalian cells into adaptive medicines that sense disease states and respond by producing combinatorial therapies, thus providing the right amount of treatment at the right place and the right time. By enabling unprecedented control over cellular function, Senti?s cell circuit technology is able to address diseases that are difficult to treat with existing drugs, making it well-suited for the control of immune-mediated diseases. Major challenges for immunotherapies are the need for to keep effects localized, spatially and temporally, in order to reduce often-serious systemic side effects. And, because the immune system is extremely complex, maximizing treatment efficiency demands the ability to target multiple systemic components. Cell circuits are a natural fit for immune-related diseases because they address all of these challenges. The feasibility of Senti?s technology has been established in animal models of several disorders including IBD. This Phase I proposal will generate proof-of-concept data for a novel technology in which an engineered genetic circuit will enable mesenchymal stem cells (MSCs) to sense the activation of a nuclear transcription factor that plays a key role in autoimmune disorders and responds by delivering anti-inflammatory therapeutics (Aim 1). After the anti- inflammatory activity of the circuits are confirmed in vitro (Aim 2), proof-of-concept data will be collected in a mouse model of an autoimmune disease (Aim 3). These results will constitute the requisite first step towards the completion of the preclinical pharmacokinetics, safety and efficacy studies enabling an Investigational New Drug (IND) application with the FDA. The market is ripe for the emergence of a new class of smart therapeutics, signaled by the converging clinical acceptance of cell- and gene-based therapies, exponential improvements in synthetic biology technologies, and growing understanding of immuno-biology. The treatment being developed under this proposal will ultimately help chip away at the financial burden of IBD, which costs Americans an estimated $14.6 billion each year and is expected to keep doubling every decade.